OK Idiot sekalian ... I have made the Research on the 4B10 and 4B11 differences .. for idiots whom wanted to do this.. Good news..
The differences is just the Piston and conrod! .. crank shaft is the same..
4B10 | 4B11
Basic diameter mm | 86 | 86 |
Pin hole diameter mm | 21 | 21 |
Overall height mm |52.66 | 50.5 |
4B11 have shorter piston then 4B10
and the conrod ..
4B10 | 4B11
Small end hole diameter (d) mm | 21 | 21 |
Big end hole diameter (D) mm | 51 | 51 |
Centre-to-centre distance (L) mm | 153.55 | 149.25 |
now back to some basic calculation.
4B10 Bore -> 86mm
4B10 Stroke -> 77.4 mm
4B11 Bore -> 86mm
4B11 Stroke -> 86mm
How do we calculate the CC ?
((PI x (Bore / 2) x (Bore / 2) x Stroke ) / 1000 ) x 4
What is PI . 3.142 ... Go google.
the last one we X4 is because it has 4 piston
((3.142 x (86/2) x (86/2) x 77.4 ) / 1000) x 4
= ((3.142 x 43 x 43 x 77.4) /1000) x 4
= (449.659) x 4
= 1798 cc
For 2.0
((3.142 x (86/2) x (86/2) x 77.4) / 1000 ) x 4
= ((3.142 x 43 x 43 x 86 ) / 1000 ) x4
= (499.622) x 4
= 1998 cc
Now look back at the CON ROD I posted
4B10 -> 153.55 mm
4B11 -> 149.25 mm
153.55 - 149.25 mm = 4.3 mm differences
if u put this 4.3 into a JEJARI (sorry I dunno what is call in English) .. in terms of diameter .. 4B11 will be 8.6 mm shorter than 4B10, which makes MORE ROOM for the stroke .
Back to the spec .. 4B10 = 77.4mm stroke ... 4B11 = 86mm stroke
86 - 77.4mm = 8.6mm
So the calculation match .
SUMMARY in layman terms... to upsize 1.8 to 2.0 .. ONLY THE CONROD is SUFFICIENT. But then if you use back the same piston, compression might be too high.
Good luck in exploring